


Choice This Time Around

by purplekitte



Category: Horus Heresy - Various Authors, Warhammer 40.000
Genre: Alpha/Beta/Omega Dynamics, M/M, Non-Traditional Alpha/Beta/Omega Dynamics, Plot What Plot/Porn Without Plot, Sex Pollen, Size Difference
Language: English
Status: Completed
Published: 2017-01-15
Updated: 2017-01-15
Packaged: 2018-09-17 17:07:21
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,004
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9334562
Author URL: https://archiveofourown.org/users/purplekitte/pseuds/purplekitte
Summary: Guilliman’s on edge from having to deal with Lorgar and Thiel offers to help.





	

Thiel was a beta and awfully glad of it. Alphas were disproportionally represented in the Legion command structure, but it was betas who made up the backbone of the bonds of brotherhood that made the Legionnes Astartes what they were, while the alphas had their dick-measuring contests and the omegas their special-snowflake specialist roles nurturing neophytes or machine-spirits or whatnot.

‘Tell me if my theoretical’s wrong: You don’t want an omega, because you want an omega too much, and no omega’s going to be able to get anywhere near you without their biology taking over. Any alpha in the Legion would present for you too, you’re _you_ , but it would play havoc with their systems. Both you and them would be getting the wrong signals the whole time and compensating for that would miss the point of trying to slip your control. You still want someone to take the edge off. Practical: I’m a beta. I want this.’

He should probably, he decided, have tried to sound a little more dignified and less desperate, but he’d wanted to get across that he was more than reluctantly giving consent to something that was the best tactical option.

‘What I would like is for my brother to not inconvenience others by putting them in such a situation,” Guilliman said acidly, gracing Thiel with such an admittance. Not that anyone could have missed Guilliman’s feelings about Lorgar. “I have no intention of treating _him_ in the disgraceful way I want to respond, let alone anyone else.'

'I trust you, sir.'

Guilliman nodded, with a hint of irony. 'Good. I didn’t give you permission to do otherwise.'

Thiel took the direct approach. He had a certain tendency to leap before he looked. ‘If anyone can give meaningful consent here, it’s me.’

He reached out to touch and only afterwards realised he should have asked permission to dare lay hands on his primarch’s august person even under other circumstances. Well, already in too deep, so he might as well do what he wanted and continue. He lifted his hand from his lord’s chest armour and reached up to touch his cool gauntlet to his bare cheek. Primarchs really were unnecessarily tall.

Whether his lord took what was offered or threw him out on his ass, he felt no fear, and not just because it had been genhanced out of him. It was total trust.

Guilliman watched him appraisingly from level blue eyes, despite the widening of his pupils from the heat of his rut. He had a primarch’s peerless mind, but he took his own damn time. He refused to be rushed or to be hasty.

He closed his own hand over Thiel’s gently, with the fine dexterity with which he could pick up an egg with his gauntlets without breaking it.

*

It took all his control to hold back, but Roboute Guilliman would never allow less from himself. As a warlord, he had hurt many, many people, but on his honour, when he did it, it would be on purpose.

Instead, he indulged by imagining how Thiel was going to look when he fucked him. That it would happen was no longer in any doubt. How his skin would feel rather than the cool ceramite of his armour, though the latter did feel good against his heated flesh. How he’d beg for him without hesitation or shame, and his mouth would surely be filthy, forgetting entirely it wasn’t proper to talk in gutter-argot around his primarch.

He leaned down and captured Thiel’s lips in a possessive kiss, arm around his waist drawing him close with a clatter of armour and holding him steady against his unyielding strength.

Thiel moaned into his mouth, eyes closing for a moment, then snapping back open to take in every detail of his face hungrily.

Guilliman had better poise, but he was hardly less affected. He wanted. His erection throbbed beneath his armour, painfully hard and aching for release. Thiel wasn’t giving back the proper omega signals that the alpha part of his brain wanted, but the smell of Lorgar’s heat had already raised his rut quite well and Thiel he wanted. Thiel wasn’t an omega, but, as he’d said, primarchs who were alphas could make betas feel like omegas around them, ordinary alpha too. It was hardly unusual for an alpha to be only attracted to omegas (he could recall the approximate statistics from Macragge) and some cultures he’d encountered considered other pairings to be obscene. Guilliman’s natural inclination was a preference for omegas, but he wasn’t so exclusive, especially when his mind was attracted even if his hormones needed a push.

‘Strip,’ he ordered, and for once Thiel rushed to obey without arguing or reinterpreting his command.

Thiel wasn’t handsome, not in the way of the Emperor’s Children for instance, but he was solid in the Ultramarine way. Guilliman liked him for his glorious disaster of a personality and the way he looked at him with unabashed eagerness and lust anyway.

Thiel didn’t wait for permission to start on his own armour when he stood naked before him. His disregard of protocol made Guilliman smile, though he understood why formality existed for social functioning and he had mandated it himself. His smile became more of a smirk as Thiel stole kisses against his skin as he worked. ‘Brat.’

‘Even your geneseed couldn’t fix that, lord.’

He pulled Thiel close, feeling the length of his body against his own, the texture of Astartes skin and muscle. ‘Then we must have some things in common.’ Sitting back on his desk, he pulled Thiel into his lap and kissed him breathless.

Then he leaned down and bit his neck, hard enough to bruise but not quite break the skin. Thiel groaned in pleasure and unconsciously mumbled a couple words most of his Legion would blush to hear. _Mine,_ Guilliman thought.

With a free hand, he retrieved a bottle of lube from exactly where he kept it in his desk. His other hand moved between Thiel’s legs as the other man straddled his hips, squeezing his arse, rolling his balls between his fingers, stroking his cock. His instincts hated the delay of foreplay, but it was necessary. Even with an omega it would have been necessary, unless that individual had also been a primarch. He refused to do Thiel the disservice of letting his mind linger overlong on the thought of taking Lorgar without holding back, or even Dorn, who was at least agreeable.

Roboute Guilliman liked to think he was a good alpha. When he was with an omega, he took care of them, gave them what they needed. He made sure of his partner’s pleasure, told them what to do and pushed them down as easily as breathing but made sure it was what they were aching for, something that wouldn’t hurt or shame them later, when the heat was over. He didn’t ignore how own rut making him want, but he wanted to do things right even more than he wanted to be inside the warm, begging body under him right that moment.

Then there was Lorgar.

Lorgar made him want for his brother to be someone other than who he was. Since that was not true or going to be, Guilliman was stuck dealing with the brother he had and wished he didn’t. Some part of him insisted that if he just got Lorgar to submit hard enough, to do what he was told and be still and listen, then everything would be right in the galaxy and between them. The other part of him just wanted Lorgar to submit.

He didn’t want to be the sort of person who didn’t care what Lorgar wanted or how much he hurt him, yet his brother brought that out in him. Lorgar being spiteful and irresponsible and _not taking his damn suppressants_ and going around the fleet in heat like a biohazard of omega pheromones with primarch intensity was _not helping_.

Focus. _He_ wasn’t Lorgar. He was stronger than his instincts. Even if he hadn’t intended for his body to be in this state of arousal, he would decide what he did with it. He was in control. Of the various practicals open to him, he had chosen to be here, now, with this impulsive Astartes who wanted him. Who had chosen him, as freely as was possible when he was a primarch with all the complications of aura and chain-of-command inherent in that.

‘Please, lord, fuck that’s good, deeper, fuck,’ Thiel was muttering into his chest as Guilliman’s fingers moved inside him, squirming against him, which made Guilliman smile.

Rubbing lube onto his cock, letting Thiel feel it between his thighs, he commented, ‘That’s only my fingers, you know.’

‘That has come to my attention, Throne you’re huge, feels so good already but I want you in me, I can take it, want you to like it.’

Guilliman grinned, already enjoying himself. He kept scissoring his fingers in Thiel and worked his cock in firm, sure strokes with the other hand. ‘I’m not getting inside you until you’ve had at least one orgasm to help you relax. Come for me, Aeonid.’

It turned out that Thiel could follow orders, with enough motivation. Guilliman kissed him long and slow and deep to express his approval, once the string of profanity had slowed down, and Thiel melted against him. ‘Good boy.’

‘Yes, lord.’

‘We’re just getting started.’

‘Oh good.’ The spark in Thiel’s eyes spoke to the idea that this had not been nearly enough to tire out an Astartes. ‘Please fuck me,’ he begged before Guilliman needed to ask him anything.

Guilliman rolled them over so that Thiel was sitting on his desk and he was leaning over him. Slowly, carefully, finally, he pushed inside him.

Thiel breathed in sharply as he was penetrated and held it for a long time, and it was only when his moans and jumbled muttering resumed that Guilliman knew he could inch forward again. He couldn’t take him all the way, he couldn’t let himself off the leash, but it was good enough, would have to be. Thiel was tight and hot around him at least, shuddering and spasming with the effort of stretching to accommodate a primarch, but not backing down in the least.

 _Mine,_ he told himself as a distraction from impatience. _My Legionnaire, my son, my lover. The man who’s not going to be able to walk straight tomorrow after I fuck him raw._

As Thiel adjusted, he pulled back and slid in again in one smooth stroke. Thiel searched for purchase on the desk, didn’t find any, and Guilliman said, ‘You can touch.’

‘Oh thank science.’ Thiel threw his arms around his waist to anchor himself and have something to hold onto, and Guilliman began fucking him in earnest.

The friction was glorious, the very act of having someone under him and taking him, moving inside a welcoming body. He jerked Thiel off again as he found a rhythm, his sweet body clenching around him with his orgasm and his gasps of shock at how good it felt. He fucked him until Thiel was an exhausted, whimpering, boneless mess against him, Guilliman holding him up to his chest to keep him from collapsing entirely. _Mine,_ he thought with each thrust inside him, each mark he left on his skin with fingers and mouth, each gasp that fell from his lips. _Mine,_ he thought as he found his own release, satiated with the idea he had thoroughly claimed him, body and mind.

Guilliman rolled them over again so that Thiel could curl against his chest without having to try to support his own weight. The Astartes cuddled with abandon, seeking his closeness, his warmth, his approval.

‘I almost want to thank your damn fool of a brother now. I mean... pretend whatever I said was more polite, my lord.’

Guilliman chuckled and stroked Thiel’s hair. ‘Never repeat this to him, but I almost agree.’


End file.
